1. Technical Field
Embodiments of the present disclosure relate generally to a smart key for a vehicle and, more particularly, to a smart key which performs a certification procedure on a vehicle and a method of controlling the smart key.
2. Description of the Related Art
A smart key system allows for opening and closing of vehicle doors from outside of the vehicle and starting the vehicle without a driver performing actions such as inserting a key into a key box of the vehicle. A smart key, which is easily portable, can be, for example, a smart card, a FOB for wireless communication, etc.
When a driver carrying a smart key approaches a vehicle, the vehicle doors can be opened without insertion of a separate key by automatically releasing a lock of the doors through low frequency (LF) communication and radio frequency (RF) communication between the smart key and the vehicle. Furthermore, the vehicle can be started without inserting a key into an ignition once the driver enters into the vehicle.
Specifically, the smart key system is typically performed by: i) a transmission process of an LF signal which transmits a certificating request signal to the smart key, and ii) a reception process of an RF signal which receives a certification response signal from the smart key. In this case, due to a transmission distance limit of the LF signal in a relatively low frequency band compared to a frequency band of the RF signal, only when the smart key is located close to the vehicle can the vehicle receive the certification response signal from the smart key.
An LF signal transmitted from a vehicle is collected by an antenna or the like near the vehicle to relay the LF signal from the vehicle to a smart key located relatively far away, and then the smart key directly transmits an RF signal to the vehicle or the RF signal is collected again by the antenna or the like to relay the RF signal to the vehicle. However, security risks exist allowing wireless signals of relays to be hacked.